1. Field of the Invention
The present invention relates to a rewritable optical recording medium system, and more particularly, to an optical recording medium having an indication of a recording capacity, and a method for indicating a recording capacity of an optical recording medium.
2. Background of the Invention
In general, the optical recording media are sorted as a ROM type for read only, a WORM type for writing once, and a rewritable type for repetitive writing. In disks which are rewritable freely and repetitively, there are CD-RW(Rewritable Compact Disc), and rewritable digital versatile disc(DVD-RW, DVD-RAM, DVD+RW).
FIG. 1 illustrates an architecture of the rewritable optical disk, provided with, starting from inside, a lead-in area, a data area, and a lead-out area. The data area is divided into zone units for random access, each zone provided with a user area and a spare area for use when a defect is occurred in the user area.
Referring to FIG. 2, the lead-in area is provided with an embossed data zone, a mirror zone, and a rewritable data zone. The embossed data zone, an area preformatted in the disk fabrication process, has a recorded data change of which is impossible. The embossed data zone in turn is provided with a blank zone, a reference signal zone, a blank zone, a control data zone, and a blank zone. The control data zone contains an embossed data field, and the data field contains embossed control data. The control data has 192 ECC (error correction code) blocks, and each ECC block has 16 sectors. A first sector in each block contains physical format information, a second sector contains disk manufacturing information, and the rest of the sectors are left unused. And, the rewritable data zone, an area provided for rewriting control information varied with data rewriting, has a protection track zone, a disk test zone, a drive test zone, a protection track zone, a disk ID (identification) zone, and defect management areas (DMA1 & DAM2) for managing defects in the disk. The optical disk has a variety of recording capacities, such as 2.6 G (giga byte), 4.58 G, 4.7 G, and etc., determined according to track pitches which are distances between pit lines.
However, the recording capacity of a disk may differ even if the track pitch and a size of the disk (for example, 8 cm or 12 cm) are identical. For example, if a spare area in a data area is employed as a user area according to a disk manufacturing process or reformatting, or according to a size of a spare area allocated, the recording capacity of the disk may differ even if the track pitch or the disk size is identical. The spare area may be fixed or varied by enlargement as necessary. Herein, one example of the disk in which the spare area is fixed is called a mode-1, and one example of the disk in which the spare area is varied by enlargement or extension is called a mode-2. In the case of mode-1, for setting an initial data recording capacity (a user area) to be 4.58 GB, the spare area is allocated to be 145 MB (=mega byte) every time. In the mode-1, the 145 MB of the spare area may be allocated on top of the user area entirely as shown in FIG. 4A, or divided to top and bottom of the user area as shown in FIG. 4B, when 25 MB may be allocated to the top and the rest is allocated to the bottom by taking interchangeability with the mode-2 into consideration. The spare area allocated to the top is called as a primary spare area (first SA), and the spare area allocated to the bottom is called as a supplementary spare area (second SA). In the case of mode-2, in order to set an initial data recording capacity (i.e., a user area) to be 4.7 GB, 26 MB is allocated as the spare area. In this instance, as shown in FIG. 4C, the 26 MB is assigned to the first spare area in formatting, a second spare area may be allocated to the bottom additionally as necessary, or may be enlarged. In every one of the foregoing operations, the recording capacity of the disk is varied. In those instances, the disk recording capacity can not be known only from a size of track pitch or disk, which impedes recording or reproduction of an accurate amount of data.